Project description:Analysis of non-differentiated Caco-2 intestinal epithelial cell line treated with polydextrose fermentation metabolites fermented for 48 hours in 4-stage in vitro colon simulator, in which the conditions mimic the human proximal, ascending, transverse and distal colon in sequence , as well as with medium, 100 mM NaCl and 5 mM butyrate. Polydextrose, a soluble fiber fermented in colon, was fermented with the in vitro colon simulator in three amounts of 0%, 1% and 2%. Results provide insight into the mechanisms underlying colon cancer cells and a comparison of a complex fiber metabolome to 5 mM butyrate and 100 mM NaCl. Furthermore, the results give insight of dosage effect of increasing the concentration of fiber. High level of dietary fiber has been epidemiologically linked to protection against the risk for developing colon cancer. The mechanisms of this protection are not clear. Fermentation of dietary fiber in the colon results in production of for example butyrate that has drawn attention as a chemopreventive agent. Polydextrose, a soluble fiber that is only partially fermented in colon, was fermented in an in vitro colon simulator, in which the conditions mimic the human proximal, ascending, transverse and distal colon in sequence. The subsequent fermentation metabolome were applied on colon cancer cells, and the gene expression changes studied. Polydextrose fermentation down-regulated classes linked with cell cycle, and affected number of metabolically active cells. Further, up-regulated effects on classes linked with apoptosis implicate that polydextrose fermentation plays a role in induction of apoptosis in colon cancer cells. The up-regulated genes involved also key regulators of lipid metabolism, such as PPARg and PGC-1α. These results offer hypotheses for the mechanisms of two health benefits linked with consumption of dietary fiber, reducing risk of development of colon cancer, and dyslipidemia.
Project description:Analysis of non-differentiated Caco-2 intestinal epithelial cell line treated with polydextrose fermentation metabolites fermented for 48 hours in 4-stage in vitro colon simulator, in which the conditions mimic the human proximal, ascending, transverse and distal colon in sequence , as well as with medium, 100 mM NaCl and 5 mM butyrate. Polydextrose, a soluble fiber fermented in colon, was fermented with the in vitro colon simulator in three amounts of 0%, 1% and 2%. Results provide insight into the mechanisms underlying colon cancer cells and a comparison of a complex fiber metabolome to 5 mM butyrate and 100 mM NaCl. Furthermore, the results give insight of dosage effect of increasing the concentration of fiber. High level of dietary fiber has been epidemiologically linked to protection against the risk for developing colon cancer. The mechanisms of this protection are not clear. Fermentation of dietary fiber in the colon results in production of for example butyrate that has drawn attention as a chemopreventive agent. Polydextrose, a soluble fiber that is only partially fermented in colon, was fermented in an in vitro colon simulator, in which the conditions mimic the human proximal, ascending, transverse and distal colon in sequence. The subsequent fermentation metabolome were applied on colon cancer cells, and the gene expression changes studied. Polydextrose fermentation down-regulated classes linked with cell cycle, and affected number of metabolically active cells. Further, up-regulated effects on classes linked with apoptosis implicate that polydextrose fermentation plays a role in induction of apoptosis in colon cancer cells. The up-regulated genes involved also key regulators of lipid metabolism, such as PPARg and PGC-1α. These results offer hypotheses for the mechanisms of two health benefits linked with consumption of dietary fiber, reducing risk of development of colon cancer, and dyslipidemia. Non-differentiated Caco-2 cells were treated with polydextrose fermentation metabolites from the vessels representing different parts of the colon, or with 100 mM NaCl or with 5 mM butyrate for 24 hours. For polydextrose fermentation three concentrations of polydextrose were used: 0%, 1% and 2% for a simulation that lasted for 48 hours. Polydextrose fermentation samples from total of 12 vessels, as well as from medium sample, 5 mM butyrate and 100 mM NaCl were analysed as single replica.
Project description:We sought to examine whether directly dietary fiber application to offspring could also reverse the behavioral and neurobiological deficits characteristic of MHFD offspring. RNA-sequencing (RNA-seq) on mice hippocampus were performed in order to identify the key biological processes and pathways regulated by dietary fiber.
Project description:To understand how dietary fiber affects microglial transcriptome at early stage, we fed mice diets releasing different amount of fiber and profiled microglia at 3 weeks. We found that fiber significantly altered the transcriptomic signature of microglia.
Project description:Despite accepted health benefits of dietary fiber, little is known about the mechanisms by which fiber deprivation impacts the gut microbiota and alters disease risk. Using a gnotobiotic model, in which mice were colonized with a synthetic human gut microbiota, we elucidated the functional interactions between dietary fiber, the gut microbiota and the colonic mucus barrier, which serves as a primary defence against pathogens. We show that during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus barrier. Dietary fiber deprivation promoted greater epithelial access and lethal colitis by the mucosal pathogen, Citrobacter rodentium, but only in the presence of a fiber-deprived microbiota that is pushed to degrade the mucus layer. Our work reveals intricate pathways linking diet, gut microbiome and intestinal barrier dysfunction, which could be exploited to improve health using dietary therapeutics. Germ-free mice (Swiss Webster) were colonized with synthetic human gut microbiota comprising of 14 species belonging to five different phyla (names of bacterial species: Bacteroides thetaiotaomicron, Bacteroides ovatus, Bacteroides caccae, Bacteroides uniformis, Barnesiella intestinihominis, Eubacterium rectale, Marvinbryantia formatexigens, Collinsella aerofaciens, Escherichia coli HS, Clostridium symbiosum, Desulfovibrio piger, Akkermansia muciniphila, Faecalibacterium prausnitzii and Roseburia intestinalis). These mice were fed either a fiber-rich diet or a fiber-free diet for about 6 weeks. The mice were then sacrificed and their cecal tissues were immediately flash frozen for RNA extraction. The extracted RNA was subjected to microarray analysis based on Mouse Gene ST 2.1 strips using the Affy Plus kit. Expression values for each gene were calculated using robust multi-array average (RMA) method.
Project description:Feeding dietary fiber is known to provide us many beneficial effects. We used microarrays to detail the changes of gene expression in colons of mice fed the psyllium fiber for 5 days.